Web conferencing is enabled by interest technologies including TCP/IP communication protocols. Services can include, e.g. multicast communications from one sender to many receivers and/or real-time point to point communications. Web conferencing can provide data streams of text based messages, voice, and video chat to be shared simultaneously, including over wide geographical areas. Applications for web conferencing include, e.g. presentations from a web connected computer to other web connected computers, training events, meetings, and lectures. Features of a web conference can include virtual whiteboard with annotation. Virtual whiteboard features allow the presenter and/or viewers to highlight items on a slide presentation. Features of web conference can include, e.g. screen sharing, desktop sharing, application sharing where participants can view any content a presenter currently has on the presenter's screen. Screen sharing applications can allow for remote desktop control, allowing participants to manipulate the presenter's screen.